Reversing mechanism



April 19, 1927. v i E ET 1,625,512

REVERS ING MEQHANI SM Filed MarohS 1924 Patented Apr. 19, 1927.

SERGIUS VERNET, 0F BROOKLYN, NEW YORK.

nnvnnsrne MECHANISM.

Application filed Marche, 1924. Serial No. 696,983.

This invention relates to an improvement in reversing mechanism, moreespecially designed for use in windshield wipers and other reversingmechanism where compactness and delicacy are prime requisites of themechanism but capable of use generally in reversing mechanism.

In my copending application Serial No. 641,853, filed May 28, 1923, Ihave disclosed a windshield wiper operating mechanism in which a warpedreversing gear driven by a constantly rotating pinion is mounted so asto slide longitudinally back and forth on the wiper rock shaft toreverse the movements thereof. Due to the enforced smallness of theparts the necessity for keeping the power consumption at a minimum andthe comparatively heavy load on the motor, considerable difficulty hasbeen experienced in securing a uniform rotational drive on the. rockshaft near the end of its swing when the pinion is meshing with thewarped portion of the reversing gear to shift the gear longitudinally ofthe shaft, with the result that the effective torque at the ends of thewiper swing may be so greatly reduced that the wiper will sometimesstick at or near the ends of the stroke and stall the motor,-especiallyif the windshield is gummy or covered with snow or ice. While thisdifficulty may be overcome by the use of properly designed gear teeth inthe warped portion of the reversing gear, it has i been found that eachtooth in the warped portion must be formed on a different cone and pitchangle and that such extreme accuracy is necessary as to render the pro-'duction of these gears very diflicult.

It is an object of the present invention to overcome this difficulty byproviding a means for. permitting the shifting of reversing gear back ad forth on the rock shaft without causing any substantial rotationalmovement of the rock shaft, so that the torque at each end of the swingof the wiper or other mechanism carried by the rock shaft will besubstantially as great or if desired greater than the torque. throughthe main portion of the swing.

Another object of the invention is to pro- 'ide a means for permittingreduced rotational drive and increased play between the driving pinion,reversing gear and rock shaft during the longitudinal shifting of thereversing gear on the rock shaft so as to reduce the wear on the guidesand other parts of the mechanism and to reduce the power consumption atthis point of the movement.

A more specific object of the invention is to provide a means which willinsure a substantially fixed relation between the reversing gear and therock shaft during the major portion of the swing of the rock shaft, butwill permit a slight relative rotation between the rock shaft and thereversing gear near the end of the rock shaft swings when the reversinggear is being shifted longitudinally of the rock shaft.

Various other objects and advantages will appear as the description ofthe invention proceeds. 7

Referring now to the drawings which illustrate one form of mechanism bywhich the invention may be practiced.

Figure 1 is a side elevation of the reversing mechanism in about themiddle of its swing.

Figure 2 is a plan view of the same.

Figure 3 a sectional view approximately on the line 3-3 of Figure 1.

In the form of embodiment illustrated 1 represents the rock shaft, tothe end 1 of which is secured the windshield wiper or other device whichit is desired to swing back and forth. A reversing gear illustrated at 2is mounted on the rock shaft, and comprises the internal bevel gearsectors 3 and 4 connected at each end by integral Warped portions 5. Aconstantly rotating pinion 6 driven by means of a gear or worm wheel 7preferably dished as illustrated, meshes with the reversing gear 2 todrive the same in all of its positions.

The reversing gear 2 is loosely mounted on the rock shaft 1, and tocause the rock shaft to turn with the gear 2 but permit the gear toshift longitudinally of the shaft, a substantially oval slot 8 is cut inthe top of the gear and a pin or screw 9 is fixed'to the rock shaft andprojectsinto the slot 8. To reduce friction between the pin 9 and thewalls of the slot a roller 10 may be provided on the pin.

The wheel 7 and pinion G are mounted on a fixed stud shaft 11 whichextends into the slot 12 formed between the feather l3 and the toothedportions 3, l and 5 of the gear 2, and guides the gear 2 in itsrotational and longitudinal movement. The wheel 7 may be driven bysuitable gearing from an electric motor or any other suitable source ofpower.

In the operation of the device, starting, from the position illustratedin Figure l, with the pinion G rotating in a counterclockwise direction,the sector I) and reel; shaft 1 is rotated to swing the wiper or othermechanism located on the end 1 of the reel; shaft in acounter-eloelvtwise direction. l l hen the pinion t3 reaches the warpedportion 5 at the end of the gear :2 which shown in Figure 1, the studshaft 11 is opposite the opening 123 between the end of the feather l3and the warped portion 5 so that the gear may be shifted to the right onthe reel; shaft to put the pinion 6 in mesh with the sector at to drivethe rock shaft in a clockwise direction until the opposite end of thesector -11: is reacl ed where the gear is again shifted lo udinallv onthe shaft to reverse the rotation of the shaft.

During the rotational or swinging movements of the shaft 1, the pin 9and roller 10 occupy a position at one end of the slot h, so that thegear 2 and the rock shalt swing back and forth in a lixed relation,during the shifting movement of the gear on the shaft, however, the pin9 and roller it) more out into the oval portion between the ends of theslot 8, which per-mite a slight relative rotational movement or plav ofthe gear on the reel; shaft, which according; to the shape of the slotEl may he made to reduce or to eliminate entirely the dririnr of theroelc shaft during the longitudinal. sh ltiue; of the gear thereon. itwill, therefore, he upjilltinii that; with the reduel ion or elimination of the drive on the I'Ut'li shaft during; the reversing movementit will no lulltlftl he i'leeessary to have sueh a2 aceurate meshlietiveen the teeth of the pinion (S and the te th in the warped portion5--and that depending on the shape of the slot .8 it may onh, heueeessary to have sullieient contact hetween the warped portions 5 andthe pinion ii to keep the teeth in mesh during the l agitudinal shiftingof the gear 53 on the shalt, consequently the necessity for carefullyformed teeth in the warped portion 5 no longer exists.

Various modifications may he made in the form of embodiments illustratedwithout de iarting from the spirit of the invention or the scope of theappended claims.

I claim 1. In a reversing mechanism of the type described, a rock shaft,a warped reversing gear thereon, means to drive the gear, in alternatelyreverse direction to oscillate the the rock shaft haul; and forth, andmeans to cause a reduction in the driving torque on the rock shaftduring the reversing movements.

2. In a reversing mechanism of the type described, a rock shaft, :1warped reversing gear, means to drive the gear to swing the rock shaftand to shift it longitudinally of the roclr shaft to offer; a reversalof the swings, and means to hold the gear iiXed on the shaft during theswinging movement and to release the gear for relative rotationalmovement of the gear on the shaftduring the reversing movement.

in a reversing; mechanism of the type described, a rock shalt, a mopedreversing gear on said rock shaft, means to drive the gear, means tocause longitudinal movement of the gear on the rocl; shaft, means tohold the gear lined against rotational movement on the lOClI shaft whenin either extreme of its longitudinal movement thereon, and means torelea.- -e the gear for a slight rota tional movement of the. gear onthe rock shaft during the longitudinal movement of the gear on the reel;shalt.

la a reversing mechanism of the type desrrihed, a rot-l; shaft, a warpedreversing gear loosely supported on said reel: shaft, an oval opening inthe huh of said gear, and a pin on said roclc shalt. projecting intosaid opening.

5. in a reverting merhauism ot the type deecrihed, a rock shaft, :1warped internal level gear loosely supported on said rocl: shaft, anoval opening through the huh of s id gear, a pin on the rock shaftproject into the opening}; and a. roller bearing on until Pill.

(i. in a revereing n'uzchanism of the type described, a root: shaft, aWarped reversing; gear thereon, means to drive the gear to eause radialmovement o if the reel: shaft, means to shift the gear longitudinally ofthe roclr shaft to reverse said mmcment, and means to eliminate theradial drive on the reel; shaft during ti o longitudinal ehi'lting ofthe gear.

in teetimon whereof I have aliixed my signature to this specification.

